Power dipper door latch trip



May-26, 11931. 1.. R. CULVER POWER DIPPER DOOR LATCH TRIP 2 Sheets-Sheet1 menfor Filed July 16, 1929 May 26, 193 1.

L. R. CULVER POWER Dl P -PER DOOR LATCH TRI-[P 2 Sheets-Shei v FiIedJuly 16, 1929 v V e Patented May 26, 1931.

' UNITED. STATES PATENT OFFICE LAGAR 1e. CULVER, or Los ANGELES,CALIFORNIA, ASSIGNOR or ONE-HALF 'ro JOHN w. PRILLAMAN AND ELLA r.Paint-amen, BOTH or jvrsre, CALIFORNIA POWER DIPPER DOOR LATCH TRIP-Application filed July s,

My invention relates to a power dipper door latch trip and has. for itsprincipal object the provision of a relatively simple and practicaldevice that may be conveniently 5 associated-with power shovels fortripping or releasing the latch that is utilizedfor holding the dipperdoor of the shovel in closed position. r

My present invention is an improvement 1o on the dipper door latch tripsor releasing devices set forth in my copending applications for U. S.Letters Patent filed August 11th, 1928, Serial No. 299,058, and SerialNo. 334,159 filed January 23rd, 1929.

Further objects of my invention are, to generally improve upon andsimplify the construction of the dipper door latch trips disclosed in myaforesaid patent applications, to provide a latch tripping device thatis capable of being readily applied to practically all makes of powershovels without altering the construction thereof or involving specialmachine work on the parts of thesli ovel, and further to provide a tripor latch releasing device-that is relatively simple in construction,inexpensive of manufacture, strong and durable and positive andefficient in opera tion.

It is the present general practice to operate the dipper door' latchesof power shovels by means of a cable, a portion of which winds upon adrum or sheave and it is one of the objects of my invention to providesimple and efficient means that will at all times and underallconditions take up the slack in the latch releasing cableand at thesame time permit the dipper to. be manipulated while being filledwithout drawing the cable sufficiently taut to release the dipper doorlatch and it is a further object of my invention to provide means undercontrol of the operator of the shovel for imparting rotary movement tothe cable carrying drum or sheave whenever it is desired to exertsufficient pull on the cable to effect a withdrawal or release of thedipper door latch.

With the foregoing and other objects in view, my invention consists incertain novel features. of construction and arrangement of parts thatwill hereinafter be more fully de- 1929. Serial No. 378,758.

scribed and claimed and illustrated in the accompanying drawings, inwhich: I Fig. 1 is an elevational view of a power shovel and showing myimproved dipper door latch release applied thereto.

Fig.2 is an elevational view partly in section of thimble that isapplied to one of the shovel control levers and which thimble, whenmanipulated, actuates the dipper door latch releasing means.

Fig. 3 is an elevational view-partly in-section of my improved dipperdoor latch releasing means.

Fig. 4 is an enlargedvertical section taken on the line 4-4 of Fig. 1;

Fig. 5 is a vertical cross section taken on the line 5 5 of Fig. 3.

Referring by numerals to the accompanying drawings which illustrate apractical embodiment of my invention, 10 designates the cab of apowershovel, which cab enclosesthe engine and the greater portion ofthe operating parts of the shovel, including the main gear wheel 11, andprojecting from-the front of the cab is the boom 12 upon which isarranged for'operation in the usual manner the.

dipper stick 13 and the latter carrying at its lower end a dipper 161that is equipped with the usual drop door 15 and said door beingretained in closed position by a latch 16.

Secured to the bolt of the latch 16 is one end of the latch releasingcable 17 that extends on suitably located pulleys 18 and 19, to awinding drum or sheave 20 that is rigidly fixed, preferably by means ofa key. to one end of a shaft 21.

Shaft 21 is mounted for rotation in a bearing 22, the latter beingformedintegral with a a bracket or plate 23 and said bracket or platebeing detachably mounted on one of the upright members of the frame orcab of the shovel.

Secured in any suitable manner to the bracket or plate 23 is a pluralityof guard fingers 24, the outer ends of which project. beyond the groovein the sheave 20 so as to retain within said groove that portion of thecable that winds unto the sheave. Secured by means of a set screw 25' onthe end of shaft 21 opposite to the end that carries sheave 20 is acollar 26 and mounted for rotary movement upon shaft 21, immediatelyadjacent to the collar 26 is the hub 28 of a gear wheel or pinion 29that meshes with the main gear wheel 11.

Rigidly fixed in any suitable manner, preferably by means of a key 30 toshaft 21 adjacent to bushing 27 and the hub 28, is the hub portion 31 ofa brake supporting arm 32. Carried by this arm 32 is a clutch 33,preferably of the type usually employed as expanding brakes'on certainmakes of automobiles and the parts of said clutch carry sections 34 ofbrake lining and which latter are adapted to engage the adjacent innerface of the rim of gear wheel 29.

. The parts of the clutch 33 are normally drawn toward each other out offrictional engagement with the gear wheel by retractile springs 35.

Mounted to move freely upon the hub 31 I i of the brake supporting arm32 and upon the hub 28 of the gear wheel 29 is the hub portion 36 of afriction plate 37, which latter lies beweb ofthe gear wheel 29andarranged between the outer portion of this friction plate and the web ofthe gear wheel is a friction ring 38 of asbestos or analogous material.

Formed in the outer face of the friction plate 37 near the hub iscircumferential groove 39 into-which projects flange 40 on the web ofthe (gear wheel 29 and which construction provi es a trap for thecollection of liquid lubricant and preventing the same from flowingoutwardly between the friction plate and web of the gear wheel intocontact with the friction ring 38. e

Journaled in one end of the clutch supporting arm'32 is a short pin orshaft 41 and mounted on the innerend thereof is a cam or eccentric 42that is positioned between the inturned ends of the two parts of theclutch 33 and which construction is common in automobile-brakes.

Secured to the outer end of shaft 41 is a short crank arm 43 thatprojects inwardly toward the shaft 21.

Formed in the brake supporting arm 32 between the bearing for theshaft41 and the hub 31 is a short arcuate slot 44 that is concentricwith the axis of shaft 21.

Seated in friction plate 37 are the inner:

ends of three or more pins45, one of which projects through slot 44 tothe side of the crank arm 43 and the outer ends of these pins 45 areseated in a thrust ring 46 that is loosely mounted on bearing 22 andwhich,

.thrust ring carries a series of antifriction bearing members 47 againstwhich engages an outer -face plate 48.

Seated in the bracket 23 directly above the bearing 22 is a pin orstud'49 and fulcrumed on the outer end thereof is the upper end ofa'yoke 5O that'exte ndsdownwardly to the sides of the bearing 22 andseated in a recess in the lower end of this yoke is an lower end of anexpansive coil spring 55 and the upper end of the latter bears againstthe underside of the horizontal arm of the bell crank lever 52.

Secured in any suitable manner to the outer end of lever 52 is one endof a flexible member 58, such as a piano wire, and this flexible memberextends through a flexible conduit 59, preferably of metal, one end ofwhich is clamped in any suitable manner to bracket 53 at apoint justbelow the end of lever 52. Secured in any suitable manner to one of thehand levers L that control the operation .of the shovel at a point ashort distance below the handle H at the top of said lever is a bracket60, on the 'side of which is fulcrumed a lever 61 and connected in anysuitable manner to the forward end of the lever is the end of theflexible member 58 that projects from the corresponding end of theflexible conduit 59, the latter being secured to bracket 60 in anysuitable manner.

Mounted upon the upper portion of bracket 60, above the rear portion oflever 61 is a set screw 62 upon which is-located a lock-nut-63 and whichscrew may be adjusted" and locked in its adjusted position so as tolimit theupward swinging movement of the rear portion of lever 61.

Mounted to slide freely upon the handle H of lever L is a tubularhousing or thimble 64, and depending therefrom is an arm 65, the lowerend of which is pivotally connected to the rear end of lever 61.

Under normal conditions orwhile the shovel is in operation gear wheel 29rotates continuously inasmuch as it is in mesh with the main drum gear11 of the shovel, but until the latch releasing mechanism is actuatcd ashereinafter described, shaft 21, to

which sheave 20 and clutch supporting arm 32 are keyed, will not rotate.

Springs 35 normally hold clutch 33 and its lining 34 out of frictionalengagement with the inner face of gear wheel 29 and the tension ofspring 51 is suflicient to act" through yoke 50, thrust bearing 46 andpins 45 to force friction disc 37 and the ring 38 against the web ofgearwheel' 29 to a sufli-- cient degree so as to rotate shaft 21' andsheave 20, thereby winding'the cable 17 unto the sheave so as tonormally take up the slack in said cable, but the contact of frictiondisc 37 with the web of gear whcel'29, as just described is notsuflicient to exert pulling strains upon the cable that would-withdrawor trip the dipper latch.

The normal friction between disc 37 and gear wheel 29 will cause saiddisc to tend to revolve with gear wheel 29, but as one of the pins 45 isin contact with lever 43 that actuates the brake band within the gearwheel, the

tendency would be to move this lever, but as a greater degree offrictional resistance is required by the disc 37 and the web of gearwheel 29, together with the resistance offered by cable 17, to overcomethe tension of springs 35, the tendency will be to revolve the brakesupporting arm 42 which is keyed to shaft21 and as sheave 20 is alsokeyed to shaft 21 it will revolve with gear wheel 29 as long as the theslack therein.

Likewise as the dipper is moved outwardly the cable will be unwound fromthe sheave 20 and placed out under the proper tension without slack.

The tension of spring 51 determines the degree of frictional resistancebetween disc 37 and gear wheel 29 and the tension of this spring isadjusted by changing the position of the bell crank lever 52 and whichlatter is adjusted by means of screw 54.

To trip' or release the dipper door latch, thimble 64 is presseddownward upon handle H, thereby rocking lever 61 and drawing flexiblemember 58 through the flexible conduit 59 so as to pull down upon thelong arm of bell crank lever 62 and as the latter is swung upon itsfulcrum it will act upon the lower end of yoke 50 to swing the same uponits fulcrum (the bolt 49) and the intermediate portion of the yoke willbear on thrust bearing 46 and 1 through pins 45 the friction disc 37will be moved into frictional engagement with the webof gear wheel 29,whichis constantly rotating.

As the friction disc 37 is, through its fric tional engagement with thegear wheel, picked up and rotated the pin 45 that is in engagement. withcrank arm 43 will swing said arm 9 a short distance, thereby rockingshaft 41 to expand the clutch and force the same into frictionalengagement with gear wheel 29, with the result that the clutchsupporting arm 42 will rotate positively and without slippage and as aresult sheave 20 will be rotated so as to wind cable 17 thereunto andexert sufl'icient pull to release the dipper door latch, therebyaccomplishing the desired result.

Spring 55 between the bell crank lever 52 and adjusting screw 54 is forthe purpose of retracting or exerting reverse pull on the flexiblemember 58 and return the thimble 64 and parts associated therewith totheir normal positions as the dipper door latch has been tripped as justdescribed.

Bolt 49 is adjustable in its support so as to regulate the position ofyoke 50 and its fulcrum.

Thus it willbe seen that I have provided relatively simple, practicaland inexpensive means that is under control of the operator of the powershovel for releasing the dipper door latch so as to permit the door toopen and discharge the contents of the dipper and which releasing meansis strong and durable in structure and capable of being readily appliedto practically all forms of power shovels without special machine workon-the shovel structure or the provision of special castings orextraneous parts.

An especially desirable feature of my invention is the mounting of thecable winding sheave or'drum' 20 upon a shaft that is not constantlyrotated directly from'the main drum gear of the shovel and in thisconnection it will be understood that the drum carrying shaft 21 is notrotated until suflicient friction It will be understood that minorchanges in the size, form and construction of the various parts of myimproved power dipper door latch trip may be made and substituted forthose herein shown and described without departing from the spirit of myinvention, the scope of which is set forth in the appended claims.

I claim as my invention:

1. In a power dipper door latch releasing device, a shaft, a windingdrum secured to said shaft, a cable secured to and adapted to wind untosaid drum, which cable is connected to the dipper door latch of theshovel with which the device is associated, acontantly rotating gearwheel mounted for rotation upon said shaft, a friction disc adapted toengage said gear wheel, a supporting arm secured to said shaft, a clutchcarried by said supporting arm for. engaging the gear wheel and meanscarried by said friction disc for actuating said clutch, said frictiontends to rotate so as to wind the cable on the drum carried thereby-andmaintain said cable under a tension insufficient to withdraw the latch.

2. In a power-dipper door latch releasing device, a shaft, a windingdrum secured to 4 said shaft, a cable secured to and adapted, to

wind unto said drum, which cable is connected to the dipper door latchof the shovel with which the device is associated, a constant lyrotating gear wheel mounted for rotation upon said shaft, a frictiondisc adapted to engage said gear wheel, a supporting arm secured to saidshaft, a clutch carried by said supporting arm for engaging the gearwheel, means carried by said friction disc for actuating said clutch,said friction disc, clutch and ch. .ch actuating means providing a slipdrive connection between said shaft and gear wheel, whereby said shafttendsto rotate so as to wind the cable on the drum carried thereby andmaintain said cable under a tension insufficient to withdraw the latch,and manually operable means for producing greater frictional engagementbetween the shaft and gear wheel, whereby sufiicient tension is appliedto the cable to release the door latch. 1 y

3. The combination with a power shovel and the latch of the dipper doorassociated therewith. of a trip cable connected to said latch, a drum onwhich said cable is wound, a shaft upon which said drum is rigidly fixedand means including a constantly rotating gear wheel that is looselymounted on said shaft for rotating the latter and the drum, a frictiondisc for engaging the gear wheel, an arm fixed to the shaft, a clutchsupported by said arm for engaging said gear wheel, means carried by thefriction disc for actuat- 'in g said clutch, which friction disc clutchand,

clutch actuating member provide means for automatically taking up theslack in said cable, but not sufliciently'to positively actuatethe cableto release the door latch.

4. The combination with a power shovel and the latch of the dipper doorassociated therewith, of a trip cable connected to said latch, adrum onwhich said cable is wound, a shaft upon which said drum is rigidlyfixed, means including a constantly rotating gear wheel that is looselymounted on said shaft for rotating the latter and the'drum, a frictiondisc for engaging the gear wheel, an arm fixed to the shaft, a clutchsupported by said arm for engaging said gear wheel, means carried by thefriction disc for actuating said clutch, which friction disc clutch andclutch actuating member provide means for automatically taking. up theslack in said cable, but not sufiiciently to positively actuate thecable to release the door latch and manually actuated means foreffectinga positive rotation of said shaft and the drum carried therebyto wind the cable unto said drum and trip the dipper door latch.

5. The combination with a power shovel and the latch of the dipper doorassociated therewith, of a trip cable connected to said latch, a drum onwhich said cable is wound, a shaft upon which said drum is rigidlyfixed, means including a constantly rotating gear wheel that is looselymounted on said shaft for rotating the latter and the drum,-a frictiondisc for engaging the gear wheel, an arm fixed to the shaft, a clutchsupported by said arm for engaging said gear wheel,means carried by thefriction disc for actuating said clutch, which friction disc clutch andclutch actuating member provide means for automatically taking up theslack in said cable,

'6. In a power dipper door latch release, a

shaft, a winding drum secured thereto, a cablesecured to and adapted towind unto said drum, which cable is connected to the latch of the dipperdoorof the shovel to which the device is applied, a gear wheel looselymounted on the shaft, which gear wheel is adapted to mesh with aconstantly rotating gear on the shovel, a support secured to the shaft,a clutch carried by said support and adapted to engage said gear wheel,means for actuating said clutch to produce a limited degree offrictional engagement between the clutch and said gear wheel andmanually operable means for increasing the degree of frictionalresistance between said shaft and gear wheel so as to rotate said shaftand the cable receiving drum carried thereby.

7 In a-power dipper door latch releasing device, a shaft, a drum securedthereto, a dipper door latch releasing cable secured to and adapted towind unto said drum a gear wheel loosely mounted on said shaft, whichgear wheel 1s adapted to mesh with a constantly rotating gear wheel onthe power shovel with which the device is associated, a loosely'mountedfriction disc adapted to engagev said gear wheel, a support fixed tosaid shaft, a clutch carried by said support and adapted to engage saidgear wheel, means 1 carried by said friction disc for causing sald'clutch to engage said gear wheel and manually actuated means foreffecting a 1 positive driving engagement between said gear wheel andshaft.

8. In a dipper door latch releasing device, a shaft, a drum securedthereto, a dipper door latch releasing cable secured to and adapted asupporting member fixed to the shaft, a

to wind unto said drum, a constantl driven member mounted for rotationon sa1d shaft,

clutch carried by said supporting member and adapted to engage saidconstantly driven member, a looselymounted manually 0011- trolled memberadapted to frictionally engage said gear wheel and means carried by saidlast mentioned member for causing said clutch to engage said constantlydriven memher.

9. In a dipper door latch releasing device, a shaft, a drum securedthereto, a dlpper door latch -releasing cable secured to and uallycontrolled member adapted to frici tionall enga adapted to wind untosaid drum, a constantly driven member mounted for rotation on saidshaft, a supporting member fixed to the shaft, a clutch carried by saidsupporting member and adapted to engage said constantly driven member, aloosely mounted manually controlled member adapted tofrictionally'engage said gear wheel and means carried by said lastmentioned member for causing said clutch to engage said constantl drivenmemher and separate means for e ectin-g a positive driving engagementbetween said con stantly driven member and said shaft.

10.- In a dipper door latch releasing device, a shaft, a drum securedthereto, a dipper door latch releasing cable secured to one 1adapted towind unto said drum, a constant- 7 said shaft, a supporting member fixedto the shaft, a clutch carried by said supporting member and adapted toengage said constantly driven member, a loosely mounted mansaid gearwheel and means carrie by sald last mentioned member for causing saidclutch to engage said constantly driven member, separate means foreffectin a positive drlving engagement between said constantlydriven-member and said shaft and manually operable means for actuatingsaid last'mentioned means.

or In testimony whereof I aflix m si ature.

riven member mounted for rotation on

